SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c007795e4b386858942ea0e7b3c36b1fd488634c5d69d1c5a60bd4196ccc4849' 
  AND token = 'xU8L8yqoXGZv+wXVRE0eUWxGg7gF2pPiNMQuykn3vag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}